CVE-2025-39910
📋 TL;DR
A Linux kernel memory allocation vulnerability where kasan_populate_vmalloc() ignores the caller's gfp_mask flags, potentially causing deadlocks when vmalloc is called with GFP_NOFS or GFP_NOIO flags. This affects Linux systems using XFS filesystem or other components that use these allocation flags. The vulnerability could lead to system instability or denial of service.
💻 Affected Systems
- Linux Kernel
📦 What is this software?
Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →⚠️ Risk & Real-World Impact
Worst Case
System deadlock requiring hard reboot, causing extended downtime and potential data corruption.
Likely Case
System hangs or crashes under specific memory allocation patterns, leading to service disruption.
If Mitigated
Minor performance impact or no noticeable effect if not using affected allocation patterns.
🎯 Exploit Status
Exploitation requires specific memory allocation patterns and kernel-level access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Patches available in stable kernel trees (commits 33b95d90427cb4babf32059e323a6d0c027610fe and 79357cd06d41d0f5a11b17d7c86176e395d10ef2)
Vendor Advisory: https://git.kernel.org/stable/c/33b95d90427cb4babf32059e323a6d0c027610fe
Restart Required: Yes
Instructions:
1. Update Linux kernel to patched version. 2. Check distribution-specific security advisories. 3. Reboot system after kernel update.
🔧 Temporary Workarounds
Avoid XFS filesystem
linuxUse alternative filesystems that don't trigger the vulnerable code path
Limit vmalloc usage
linuxConfigure system to minimize vmalloc allocations with GFP_NOFS/NOIO flags
🧯 If You Can't Patch
- Monitor system logs for memory allocation failures or deadlock indicators
- Implement system redundancy and failover mechanisms to minimize downtime impact
🔍 How to Verify
Check if Vulnerable:
Check kernel version and verify if patches are applied. Vulnerable if using unpatched kernel with XFS or similar.Check Version:
uname -rVerify Fix Applied:
Verify kernel version includes the specific patch commits or is from a distribution that has backported the fix.📡 Detection & Monitoring
Log Indicators:
- Kernel panic messages
- System hang/crash events
- Memory allocation failure logs
Network Indicators:
- Service unavailability alerts
SIEM Query:
source="kernel" AND ("deadlock" OR "vmalloc" OR "GFP_NOFS" OR "GFP_NOIO")